D scratch. To test whether using pre-trained weights for the sketch discriminator \({D_Y}\)  is necessary, we evaluate a variant with \({D_Y}\)  initialized randomly. We observe a huge decrease in performance in most cases. This indicates that pre-training in discriminators is important even when switching the training domain from images to sketches. The finding is consistent with prior work on few-shot GAN finetuning [1]}, [2]}.
